AN/ there's a chapter in ASAS (ch56) that ties in with this a little. If you're interested.

Chapter 173: The Weight of Terrible Things

He thought he knew why his head hurt.

"Riku, don't listen to what your heart is telling you—"

Hadn't this happened before?

"—it's only telling you lies."

Why wouldn't the memory stop?

"Y'know she was lying, right?"

He almost wanted to believe it…

"It's all she's good at, anyways."

Better yet, he wanted this torture to stop.

"...the girl you're dying to keep safe. The girl you love—"

He just wanted it to stop.

He wanted to curl in on himself until it all went away.

He wanted to…

But what was that? Something else. Besides the memory. Pulsing at the back of his mind. No. Not pulsing. Screaming.

"Please, that's three today. That's more than—"

"NO! I need to-"

"Namine!"

What? What was… was she… she was hurting. He could feel it. Pounding in his skull, tearing at his chest, burning in his mind. Some good he was, at keeping her safe.

"I won't let them do this!"

But she was…

"You don't love me."

No.

He was imagining things.

He was…

…on the ground.

When had he gotten there?

He sat up, quickly, only to yell in pain. His shoulder didn't like being moved that way, apparently.

"Careful!" Aerith warned.

...Aerith!?

He turned to look at her, a little confused. How long had she been there? How long had he been here? What?

He grabbed his shoulder, mainly out of habit, but Aerith smacked his hands away.

"Let me look at it," she said, firmly. After a few seconds of near-agonizing pain, something in his shoulder popped, and Aerith let out a long breath of annoyance. "You must've fallen on it when you collapsed. It was out of place again." She tsked, her expression caught between annoyance and… something else. Confusion? Despair?

(But it had to be out of place because he fell—the last time he'd tugged on it was… It didn't matter. He never did it hard enough for that, even if he wanted to.)

"C-collapsed?" he asked, having no memory of doing that. He let out a sharp gasp of pain as Aerith popped his shoulder back into place. Would that ever not hurt?

Aerith didn't answer, and instead put her hands in her lap, sighing. "Are… you okay?" she asked.

"…my head is on fire."

"I can give you a panacea. That might help."

Riku took the bottle from her and downed it without question. It only dulled the pain, but he supposed that was enough. At least the memories had stopped. Kind of.

"Do you have anything to stop memories?" he asked.

"I…" Aerith blinked rapidly a few times. "What?"

Riku realized then how odd of a question that must have been. Not really wanting to explain, he quickly shook his head. "Never- never mind," he said. "Don't worry about it."

Aerith blinked a few times more, then shook her head as well, deciding to let it go.

"I guess… I should head downstairs and make lunch," she said. "I'm… assuming you don't want any."

He shook his head.

"Do you want to come down anyway? Maybe help out or something?"

"Uhm…"

Well, any distraction was welcome, at this point, so.

"Yeah, why not?"

xxx

He was here for other reasons. Really. He'd just gotten a lead on Sora, and had come to talk to Kairi. Because… he hadn't talked to her in a while. And he wanted to see her again. Tell her that he was getting closer to find that "friend" of his. Getting closer to finding Sora.

Not that he'd mention Sora. But maybe he'd tell her not to worry.

Though… finding Sora meant dragging him into darkness—the charade had gone on long enough at this point—which meant Kairi wouldn't see him again. Right.

(He tried not to remember their pinky promise, and how much this situation burned.)

He came up to her campsite. She and Tifa were both asleep, not far from a long-dead fire. He guessed he'd just… wake Kairi up. Ask her to go on a walk with him. Or—

His heart thudded. Now that he was looking at her… He didn't know what it was. But suddenly he just wanted to wrap his hands around her neck and choke the light out of her. Strangle the hope from her eyes. Squeeze the breath from her lungs.

She was the only thing holding Sora up.

She was the only thing standing between Sora and his fall into darkness.

She was the only—

No!

He held himself back, only barely, digging his teeth into his lip, not that he bled, and the pain only did little to slow him down. His head was pounding, and it was hard to focus. He wanted her dead.

But he couldn't.

She was Sora's only anchor in this world.

Which made her the only tie that kept Maleficent from completely smothering Sora with her darkness.

Kairi was the only thing keeping Maleficent from doing his job.

Because if Sora was going to fall into darkness, it would be by his hand, not the hand of that filthy witch!

He tried to tell himself that. To calm himself down.

But he couldn't hold himself back. He wasn't tame. Not without purpose. Not without Sora. It was rage in his blood and fire in his mind, burning every thought that didn't involve crushing the life out of Sora's precious light.

And the next thing he knew, he was kneeling next to her, fingers twitching, darkness pulsing. He could just shove it into her heart—a quick strike, and that'd all it'd take, and…

He could do it.

He could kill her.

He could—

But something pulled on his chest, and his vision blurred. He had to hold back a cry of pain, nearly collapsing because of it. Something was raging through his head. His body. It wasn't anything he was used to feeling.

It was disgust. Horror. At himself. He suddenly felt despicable. Cripplingly awful. The thought of being looked down on crushed him so hard he thought he was going to puke.

He didn't want to feel this way.

He didn't want to be looked down on by him, of all people.

And now he did hate himself.

Because since when did he care what Sora thought of him? How would Sora even know? The bond between them was fractured, stiffled. Sora would never have to know who did the deed, and even if he found out, he'd be drowned in darkness so quick after that it wouldn't matter.

But…

There was no denying that the thoughts rushing through him absolutely belonged to Sora. Somehow, in this moment, Sora's thoughts reached him. More than that, they pounded through every inch of him, searing themselves into his skin. Disgust. Horror. Hatred—no. Not hatred. Pity. Disappointment.

And suddenly Sora's Shadow couldn't breathe.

He clutched his chest, trying to force the air back into his lungs. Sora's opinion did not matter.

Not to him.

Never to him.

But when everything cleared, and he found himself with his palms pressed into the grass, leaning backwards and nearly collapsed. He felt—nothing. The overwhelming desire to kill Kairi was gone.

"You're lucky," he spat, voice a whisper so he wouldn't wake her. "I need you unharmed."

That was a lie.

But he'd do everything he could to convince himself that the only reason he decided to leave her be was this reason. No other reason.

"You are his only anchor," he continued, chest tight, stomach roiling. "You are his only link away from that filthy witch, and I need that."

In his heart, he knew better.

He didn't leave her be because he still needed her.

He left her be because Sora would've.

He left her be because Sora's disappointment in him was consuming, and he wanted anything to not have to feel it.

xxx

"So I guess you're heading home tomorrow, huh?" Yuffie asked. She was busy doing something in the kitchen.

"Not technically home," Riku mumbled. He was sitting at the dining room table, fiddling with a fork that Yuffie had left sitting there.

"Day after tomorrow, actually," Aerith corrected. She was… also in the kitchen. Figuring out lunch for Cid and Leon, had she said was doing?

"Well, if you're leaving so soon, then I guess now's as good of a time of any," Yuffie said, setting a plate down on the table in front of Riku.

He glanced up at her, confused, dropping the fork. "Uhm…" He shifted his attention back to the grilled cheese sandwich now sitting before him. He swallowed. Right… how to tell her that he particularly didn't want it?

"Just try a bite!" Yuffie sat down across from him. "Please? If you don't like it, we can make Cid eat it."

Riku sighed, but, not having the energy to get into an argument with Yuffie, he took a bite of the sandwich. It actually wasn't half bad.

"What do you think?"

"I… uhm, it's good," he said. "It's, uh, really good?"

Yuffie missed the tone of confusion in his voice, and just burst into a grin. "Yay! I made it just for you."

"What'd you put on it?" Aerith called from the kitchen.

"Swiss cheese and pastrami," Yuffie replied, seeming to get uncomfortable all of a sudden. "I mean, it's going to go bad if no one eats it! And Riku doesn't seem to care!"

Aerith didn't reply. Riku slowly took another bite of his sandwich.

"So, what are you gonna do when you go back?" Yuffie asked.

Riku shrugged, swallowed. "Uhm, depends on the results of the experiment, really," he said. "If my absence didn't seem to have an effect on her meltdowns, then I don't know. We might run the test again to be positive, or we might just wait until we have a better way of determining this. If the results are inconclusive, then I guess we'll do something similar."

"And if your absence did have an effect…?"

Riku shrugged again.

"Well, then I guess I'll figure out how we're gonna stay separate," he said. "I mean, I can't leave Castle Oblivion, because I'm still needed there, but Namine could go somewhere. I guess."

Yuffie raised her eyebrows. "Is she going to be okay with that?"

"I… I dunno." Riku sighed and rubbed his head, setting the sandwich down. If the argument they'd gotten into before he left was any indication, the answer to that was no. No, she wouldn't be okay with it. "I guess we'll have to talk about it."

Except he knew that wasn't going to happen.

He ran a hand through his hair, frustrated. "Maybe… maybe we'll wait," he muttered. "'Til the Rebellion's over. Then- then we'll worry about. Then we'll have… a better idea of what's going on, and maybe she'll have… have warmed up to the idea… or…"

Yuffie stared at him. He flopped back in the chair, at a loss.

"I don't know," he said. "We'll have to talk about it, I guess. If anything… I guess I will just wait until the Rebellion's over… then deal with it. I mean, at worst, I just… leave her. There are plenty of worlds. I wouldn't mind living on the move."

"I don't think Namine'd be too happy about that…" Yuffie said, slowly.

He shrugged. It didn't matter. Her safety came before her happiness.

"I promised I'd get rid of everything that was hurting her. That never excluded myself."

Yuffie didn't say anything.

"Are you sure you want to leave her, though?" Aerith asked, voice quiet, unreadable.

Riku didn't get a chance to answer. The front door slammed open, an angry Cid making his way in, followed by a disgruntled Leon.

"If you'd just let me look at it—"

"Tha' house is gonna collapse by the time you're done 'lookin' at it'! We need teh get repairs done, and we need teh get 'em done now!"

Aerith gave one last—sad?—look at Riku before heading to go figure out what they were yelling about.

Riku just sighed, picking the crust off his sandwich, having lost his appetite.

He just wanted her safe. Why was that so hard for everyone to understand?